The designer of this arm bag (18*9.5*4cm) is designed according to the shape of our human arm and is inspired by two colors to design a front hidden zipper bag. The fitness armband and exercise band are made from skin-friendly, breathable air mesh and stretch-resistant neoprene polyester fabric blended with water-resistant, sweatproof, and washable functions, providing a soft, odor-free, and lightweight wearing experience. This running zipper pouch with double deck and double zipper exercise pouch plus size design provide a large and safe space for your cellphone as well as your house or car keys, ID/credit cards, cash, earphone, iPod, Mp3, passport, cable, facial tissue, and other accessories whilst doing outdoor activities.